Biotechnology Bulletin ›› 2026, Vol. 42 ›› Issue (1): 13-30.doi: 10.13560/j.cnki.biotech.bull.1985.2025-0643

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Biological Functions and Regulatory Network of SLR1, a Negative Regulator of Gibberellin Signaling in Rice

FEI Si-tian1,2(), HOU Ying-xiang1,2, LI Lan3, ZHANG Chao1,2()   

  1. 1.Nanling Research Institute for Modern Seed Industry, Xiangnan University, Chenzhou 423000
    2.Xiangnan University-Chenzhou Industrial Technology Research Institute, Chenzhou 423000
    3.School of Pharmacy, Xiangnan University, Chenzhou 423000
  • Received:2025-06-19 Online:2026-01-26 Published:2026-02-04
  • Contact: ZHANG Chao E-mail:feisitian@xnu.edu.cn;ricezhangchao@xnu.edu.cn

Abstract:

Gibberellins (GAs) are a class of important regulatory hormones in plants, widely involved in various life processes such as plant growth and development, and responses to stress. The regulation of GA biosynthesis and signaling pathways contributed to the first green revolution in crop breeding. SLR1 is the only DELLA protein in rice, serving as a key negative regulator in the GA signal transduction pathway that represses downstream GA signal transduction. SLR1 also participates in hormone pathways such as abscisic acid (ABA), jasmonic acid (JA), brassinosteroid (BR), and strigolactone (SL), acting as a "molecular bridge" for plant hormone crosstalk. However, the SLR1 protein lacks a typical DNA-binding domain, and there is currently no evidence indicating its ability to directly bind to DNA sequences. It mainly exerts its modulatory functions by interacting with other transcription factors to inhibit or activate the expressions of downstream genes. In addition, the expression and function of SLR1 itself are also subject to multiple regulations. At the transcriptional level, the SLR1 gene is negatively regulated by transcription factors such as OsYABBY4 and OsWRKY36; at the protein level, SLR1 undergoes modifications including ubiquitination, glycosylation, SUMOylation, and phosphorylation, as well as regulation of its own stability and activity through interactions with other proteins. SLR1 not only extensively regulates various growth and development processes but also participates responses to multiple biotic and abiotic stresses in rice, playing an important role throughout the entire growth cycle of rice. Recent research has revealed the great potential of SLR1 in breeding: regulating the protein abundance of SLR1 in rice and maintaining it at a moderate level is of great significance for improving rice tolerance to alkali and heat stress. This article mainly reviews the molecular structure and mechanism of action of SLR1, its crosstalk role in various plant hormone pathways, the protein modifications and regulations of SLR1 itself, as well as its specific biological functions. It aims to further explore SLR1-associated components and regulatory networks, providing references for rice molecular design breeding.

Key words: rice, SLR1 protein, gibberellin, hormone crosstalk, protein modification, regulatory network, biological function, abiotic stress